1. Field of the Invention
The field of the invention is that of wired networks for the distribution of signals, notably for the simultaneous and/or alternative distribution of several types of signals including, notably, audio-visual signals comprising, among others, baseband image signals or, again, computer data. This type of network is designed essentially for in-house applications, for example for the setting up of internal networks for the distribution of signals in individual or group dwellings, firms etc.
2. Description of the Prior Art
This type of network is formed by wired transmission lines running between the connection points of data emitting and receiving devices. Several emitters can simultaneously feed the network with data available for the receivers.
One of the essential characteristics of networks of this type is that they have to permit the establishing of multiple-point links through which several receivers of the network simultaneously tap one and the same signal coming from a common emitter on the network. A network such as this should furthermore be capable of simultaneously routing several multiple-point links of this type simultaneously.
Another essential characteristic of these networks is that they should offer a possibility of easy configuration of the established links, making it possible to cope with the shifting or addition of emitting or receiving instruments to the network. They should also offer a facility of selective connection, of each receiver connected to the network, to the signals emitted by one emitter or another in the network.
There are numerous transmission systems for audio-visual signals, using different media such as coaxial cables or optic fibers. These known systems set up point-to-point links, for which the signals are available solely at the ends of the medium.
Furthermore, existing media designed to transmit signals of images in baseband are operational over only a few meters. This is the case for TV peripheral cords which cannot go beyond a few meters. When it is sought to broadcast signals in a dwelling, it has therefore been deemed to be necessary, until now, to make use of a cascade of point-to-point links or, again, to use distributors associated with point-to-point links. It is also possible to set up systems that work by multiplexing, the price of this being a relative complexity.
Furthermore, there is a known method for the simultaneous transfer of signals among modules of an electronic unit, as described in the French Pat. No. 86 05759 filed on Apr. 22, 1986, on behalf of Isaac Lellouche. The method of this prior art document consists in linking the electronic modules by useful signals transmission lines, and lines for the transmission of control signals for the interconnection of the modules, this interconnection being provided by switching matrices interposed between each module and the lines for the useful signals transmission lines. Each interconnection state can be configured, on a point-to-point basis, by means of codes for the definition of each connection transmitted on the control line.
This known method is described more precisely in relation with the making of interconnected rack, frame or rack wirings. In this type of application, the length of the links does not exceed one meter. Moreover, this method is not suited to the simultaneous transmission of several different types of signals.
The adaptation of a system such as this and, more generally, the making of an audio-visual signals transmission network, in in-house application, raises a number of problems.
Thus, an approach must to be found, enabling the transmission of signals emitted in wideband, such as baseband video signals, over distances of several tens of meters.
It is also necessary to find an approach to the problem of the multiple tapping of a signal on one and the same network line, without causing mismatching phenomena.
Finally, means and procedures must be provided for the identification and interconnection of the devices connected to the network, liable to be used by the user of the in-house network.